BL29 BOREAS (formerly XMCD)
Beamline fOr REsonant Absorption and Scattering
The variable polarization soft X-ray beamline is dedicated to polarization dependent spectroscopy (absorption and scattering). It will be equipped with two end-stations for magnetic dichroism (XMCD/XMLD) and resonant soft X-ray scattering (RSXS).
Status
Beamline under construction
The installation of the main optical components of the beamline has started on the 8th February 2010 and should be completed by May 2010. The end-station for dichroism has reached the final design stage and will soon be in production, with expected delivery in October 2010. The scattering end-station is currently in its design phase.
Photos of the installation of the infrastructure (July-October 2009)
Photos of the installation of the main optical components (January - ... 2010)
Staff
Scientists: Alessandro Barla and Manuel Valvidares
Soft x-ray beamlines supervisor: Eric Pellegrin
Mechanical engineer: Daniel Bacescu (shared with Mistral)
Mechanical technician: Juan Francisco Moreno Cañamero (shared with Circe)
Electronics engineer: Julio Lidón Simón (shared with all other beamlines)
Controls engineer: Jairo Moldes Fuentes (shared with the Accelerators Division)
Beamline characteristics
| Photon energy range | 80 to >3000 eV |
| Calculated flux at the sample (at a resolving power of 5000) |
2x1013 photons/s @ 150 eV 8x1012 photons/s @ 700 eV 5x1012 photons/s @ 1500 eV 2x1012 photons/s @ 2000 eV 4x1010 photons/s @ 3000 eV 5x109 photons/s @ 4000 eV |
| Maximum resolving power |
15000 for 80 eV < E < 1500 eV 5000 for E > 1500 eV |
| Beam size at the sample | variable between a minimum of 100(H)x20(V) micron2 and >1x1 mm2 |
The beamline is optimized for highest photon flux and energy resolution in the range between 150 eV and 2000 eV. However, the monochromator and undulator allow us to reach a lowest energy of 80 eV in circular polarization, thus covering the Si L edges. Above 2000 eV, the optics of the beamline has a reduced performance as compared to typical hard x-ray beamlines, but the flux and energy resolution should be high enough to perform x-ray absorption experiments at important edges (L edges of all the 4d metals and the M edge of U) and non-resonant x-ray diffraction, to be used as a complement of resonant soft x-ray diffraction.
The HU71 undulator might be used as a wiggler for energies above the cut-off of the first harmonics (about 1000 eV), improving the flux in elliptical polarization especially for energies above 2000 eV.
